Here is how Devin Pitcher, one of our engineers who sits on a Solaris Intel box all day, sets up his Understand.
He has two monitors. His left monitor is devoted to source code and information about where he is in the source code (the C.I.S.):
On his right monitor he has organized a set of undocked information palettes. He has the Project Browser available for quick traversing around the project tree. He has the Entity Filter up, set to filter on Functions. He has the Architecture browser setup to browse based on a Architecture it automatically derives while analyzing the source. And he has the Selector window up for quick access to any files he has open. In the middle, with plenty of space to show full reference text he has an Information Browser setup to sync so that any entity he clicks on will have its information shown there.
This setup is pretty common among our engineers. Source on one big monitor (often vertically oriented) and information/navigational aids on another monitor.
Thanks for sharing Devin!